A number of 'liquid medicine dispensers' were found on board a bus yesterday on the 39a route and a passenger complained to the driver of the route.

There were no needles found with the attached dispensers. Pictures began circulating on social media outlets yesterday with many speculating as to the authenticity of the image.

Dublin Bus confirmed the incident, releasing a statement saying: "A passenger reported the dispensers to the bus driver, who immediately followed the protocol for such incidents.

"The driver informed Operations Control, the vehicle was immediately taken out of service and passengers transferred onto another bus. The vehicle was then brought to its garage and thoroughly cleaned as per the strict guidelines that are in place.

"Dublin Bus has downloaded the CCTV footage from the vehicle and is investigating the matter."

Dublin West Fianna Fáil Councillor David McGuinness has called on Transport Minister Leo Varadkar to launch a full scale investigation.

"The public health implications of syringes and blood lying around is a major concern for members of the public," he said. "They expect nothing less than a full investigation and for measures to be put in place that this will not happen again. The truth is that drivers are fearful to confront passengers who pose risks to themselves and others."